Epidemiology

Fractures in the pediatric population are common. An annual fracture incidence of 180 per 10,000 in children younger than 16 years has been reported. Fractures of the distal radius were found to be the most common, representing 31% of all fractures in this patient population and tended to occur in the nondominant extremity in roughly 53% of cases. The mean age at the time of fracture was 9.3 years in girls and 10.4 years in boys. Pediatric fractures are more commonly seen in boys, with a male to female incidence ratio of 1.5.

Distal radius fractures most often occur as a result of a fall onto the outstretched hand. Randsborg and colleagues reported that activity-related fracture was most common during soccer and the highest fracture rate involved snowboarding. Snowboarding conferred a fracture risk 5 times greater than during trampoline-related activities and 4 times greater than in soccer. Other activities with high fracture risk include handball, rollerblading, and playground activities.

Clinical Evaluation

Initial evaluation of the patient with injury to the wrist and forearm should focus on the soft tissue and neurovascular status. The area of injury must be meticulously inspected for abrasions, lacerations, and the possibility of an open fracture. Although soft-tissue swelling is expected in the setting of musculoskeletal trauma, the clinician should evaluate the forearm compartments and remain vigilant in identifying a developing compartment syndrome. Compartment syndrome in the uncooperative pediatric patient can, at times, be difficult to detect. Cardinal signs of an acute compartment syndrome in a child include an agitated , inconsolable child appearing anxious and requiring an increasing amount of analgesia . This condition can be remembered conveniently as the “Three A’s” of pediatric compartment syndrome. Perfusion of the distal extremity may be evaluated by examining radial artery pulse, capillary refill, and temperature of the digits. Neurologic examination consists of inspecting for sensory deficits in the radial, ulnar, and median nerve distributions. Although difficult to assess in a pediatric patient in an acute fracture setting, an attempt should be made to evaluate the anterior interosseus, posterior interosseus, and median and ulnar nerve motor function. The remainder of the involved extremity should be carefully evaluated for concomitant injury, as the patient often may be distracted by their most painful injury.

Plain film imaging of the distal forearm fracture is, in most cases, sufficient for diagnosis and management of distal forearm fractures. It is imperative to obtain adequate anterior-posterior and lateral views of the fracture site. If physical examination reveals pain or decreased range of motion in other sites, additional imaging should be obtained to rule out associated fractures. Computed tomographic (CT) scan and MRI have a limited role in the acute fracture setting but may be useful in the management of chronic sequelae, such as malunion and growth arrest.

Epidemiology

Fractures in the pediatric population are common. An annual fracture incidence of 180 per 10,000 in children younger than 16 years has been reported. Fractures of the distal radius were found to be the most common, representing 31% of all fractures in this patient population and tended to occur in the nondominant extremity in roughly 53% of cases. The mean age at the time of fracture was 9.3 years in girls and 10.4 years in boys. Pediatric fractures are more commonly seen in boys, with a male to female incidence ratio of 1.5.

Distal radius fractures most often occur as a result of a fall onto the outstretched hand. Randsborg and colleagues reported that activity-related fracture was most common during soccer and the highest fracture rate involved snowboarding. Snowboarding conferred a fracture risk 5 times greater than during trampoline-related activities and 4 times greater than in soccer. Other activities with high fracture risk include handball, rollerblading, and playground activities.

Clinical Evaluation

Initial evaluation of the patient with injury to the wrist and forearm should focus on the soft tissue and neurovascular status. The area of injury must be meticulously inspected for abrasions, lacerations, and the possibility of an open fracture. Although soft-tissue swelling is expected in the setting of musculoskeletal trauma, the clinician should evaluate the forearm compartments and remain vigilant in identifying a developing compartment syndrome. Compartment syndrome in the uncooperative pediatric patient can, at times, be difficult to detect. Cardinal signs of an acute compartment syndrome in a child include an agitated , inconsolable child appearing anxious and requiring an increasing amount of analgesia . This condition can be remembered conveniently as the “Three A’s” of pediatric compartment syndrome. Perfusion of the distal extremity may be evaluated by examining radial artery pulse, capillary refill, and temperature of the digits. Neurologic examination consists of inspecting for sensory deficits in the radial, ulnar, and median nerve distributions. Although difficult to assess in a pediatric patient in an acute fracture setting, an attempt should be made to evaluate the anterior interosseus, posterior interosseus, and median and ulnar nerve motor function. The remainder of the involved extremity should be carefully evaluated for concomitant injury, as the patient often may be distracted by their most painful injury.

Plain film imaging of the distal forearm fracture is, in most cases, sufficient for diagnosis and management of distal forearm fractures. It is imperative to obtain adequate anterior-posterior and lateral views of the fracture site. If physical examination reveals pain or decreased range of motion in other sites, additional imaging should be obtained to rule out associated fractures. Computed tomographic (CT) scan and MRI have a limited role in the acute fracture setting but may be useful in the management of chronic sequelae, such as malunion and growth arrest.

Metaphyseal Fractures

See Fig. 1 for 4 different examples of metaphyseal fracture patterns.

Distal radius metaphyseal fractures. ( A ) Greenstick fracture, ( B ) buckle fracture, ( C ) complete, nondisplaced fracture, ( D ) complete, displaced fracture.

Bicortical Fractures

Displaced fractures

Patients with displaced fractures of the distal radius metaphysis typically present with a deformity of the wrist. Skin compromise at the fracture site, such as a small laceration or an abrasion with active bleeding, may indicate an open fracture. Neurovascular examination must be documented before reduction is attempted. Because most displaced fractures demonstrate dorsal displacement, the clinician should assess for volar wounds and median nerve injury. Sterile dressing of open wounds and provisional splinting should be done in the emergency department before obtaining radiographs to lessen the risk of ongoing soft-tissue injury and for patient comfort.

Closed reduction

Displaced fractures are best treated with closed reduction and immobilization under conscious sedation in the emergency department. Fracture reduction may be facilitated by re-creation of the deformity that would relax the intact periosteum on the compression side of the fracture and allow the distal fracture fragment to slide over the proximal fragment. A well-molded sugar tong splint or cast would help maintain the reduction. When a cast is applied in the acute fracture setting, consideration should be given to bivalve the cast to accommodate subsequent swelling ( Fig. 2 ).

A 5-year-old girl fell from tricycle and sustained a fracture of the distal radius and ulnar metaphysis with apex volar angulation ( A , B ). The child underwent closed reduction and casting in the emergency room under conscious sedation. Follow-up radiograph at 2 weeks demonstrated a well-maintained reduction ( C , D ). Eight weeks after injury, radiographs reveal a healed fracture in anatomic alignment ( E , F ).

After reduction and application of a cast or splint, postreduction radiographs and a repeat clinical examination are mandatory. Most patients may be discharged home with fracture care instructions. Those patients with significant pain, severe swelling, abnormal findings on examination, or a potentially unsuitable home environment are best observed in the hospital overnight. On the hospital floor, instructions are given for strict wrist elevation, frequent neurovascular checks, and pain control that permits reliable evaluation but does not mask the signs of an evolving compartment syndrome or acute carpal tunnel syndrome.

Acute carpal tunnel syndrome, although rare in the pediatric population, has been reported after Salter-Harris (SH) 2 fractures of the distal radius. This complication is most common after dorsally angulated and displaced metaphyseal or physeal distal radius fractures in older children and adolescents. Patients developing acute carpal tunnel syndrome initially present with parasthesias in the sensory distribution of the median nerve. Differentiating a contusion to the median nerve from acute carpal tunnel syndrome can be challenging. The diagnosis is largely clinical and relies heavily on the progression of symptoms. A median nerve contusion presents as numbness or tingling in the volar aspect of the thumb, index, and long fingers that begins immediately after the injury. The symptoms are nonprogressive and tend to respond to elevation of the extremity and loosening of the dressings. Carpal tunnel syndrome, on the other hand, presents as a gradual progression of symptoms over a few hours after injury. The patient reports no relief with elevation and loosening of dressing. In the setting of progressive median nerve symptoms unrelieved by elevation, an urgent carpal tunnel release is indicated.

Acceptable Reduction of Metaphyseal Fractures

The distal radial physis accounts for 60% of the growth of the radius and typically closes at 14 to 16 years of age. A significant and predictable amount of remodeling occurs in fractures that heal with angulation and displacement if the physis is not injured. Acceptable reduction parameters vary with age ( Table 1 ).